Motion Input Triggered Accidentally by Hand Tremors

2.5.4 — Motion Actuation

Scenario

A photo-sharing app's upload screen

Motion input that can be triggered accidentally (tremor) with no setting to turn it off.

window.addEventListener('devicemotion', (e) => {
  if (e.acceleration.x > 3) undoLastEdit(); // threshold is low, and there is no off switch
});

Someone with a hand tremor loses their last filter adjustment just from ordinary shaking while holding the phone.

Hold the device with a slight natural tremor: if the motion feature triggers accidentally with no setting to turn it off, it fails.

Motion sensitivity thresholds are too easy to trip involuntarily; make an explicit undo button the default path.

<button onclick="undoLastEdit()">Undo</button>
// the devicemotion listener is removed, or gated behind a settings toggle that defaults to off

A user with tremor edits photos without losing work to accidental shakes.

People with Parkinson's, essential tremor, or any condition causing involuntary hand movement.